Clow Book

The Clow Book is a book containing a collection of mysterious and powerful magic cards titled "Clow Cards". originally owned by Clow Reed. It is first seen on Episode 1 when Sakura Kinomoto goes inside of their house's basement after hearing a loud noise coming from the basement.

The book's cover is designed as a golden lion named Cerberus which is the guardian of the Clow Cards. When Sakura opened it, she first saw The Windy card, and she reads its name loud, causing the cards to escape the Clow Book where they are scattered all over the city.

Meanwhile, Cerberus takes material form in his disguise of a plush toy or stuffed animal, after awakening from his deep sleep and upon realizing what's happening, appoints Sakura as the Card Captor, the one who will recapture the Clow Cards.

The Clow book has its own arrangement of cards. The total number of cards is "52", which means The Nothing and The Nameless card, together with The Hope card, are not one of the official Clow cards, and The Nameless and The Hope card do exist in Sakura Cards, and not in Clow Cards.